DETROIT — Even amid increased scrutiny, former Sen. Rick Santorum unapologetically wears his faith-fueled social conservatism on the heart of his trademark sweater vest.

But the same steely resolve that boosts him with the Republican Party's sizable social conservative bloc could also be a huge liability among moderate voters — and among independents that a GOP candidate would need to win the general election.

Santorum is against legalized abortion, even in a case of rape or incest, and opposes same-sex marriage to the point that he's made statements in the past that seem to equate homosexuality to polygamy and incest. He disapproves of gays serving openly in the military and of women in combat roles; warns of the dangers of prenatal testing; and is personally against manufactured contraceptives because, he says, they are a contributor to the breakdown of the traditional American family.

In Michigan, an important swing state that holds its Republican presidential primary on Tuesday, many voters sympathize with Santorum's views. But many also worry that his social conservatism will alienate too many voters and make it hard to beat President Barack Obama in November.

"He's extreme in his views on abortion," said Deloris Newell, a Roman Catholic Republican who lives in Canton Township near Detroit. "And don't tell me what God to worship. ... You cannot be an extreme liberal or an extreme conservative to win an election."

"And the media complains so much about these structured candidates and how they are all robotic," he said. "And then of course they have a candidate that doesn't do any of those things, they say, 'Oh, he's really out there, you have to worry about what he says.' No you don't, because I will defend everything I say."

But the more he does, the more questions he raises in the minds of many voters, particularly Republican and independent women.

"He tends to be strident about the social issues — the way he talks about it doesn't give you any confidence," said former Rep. Nancy Johnson, a moderate Republican from Connecticut who supports legalized abortion and served with Santorum for four years in the House of Representatives.

"The president helps govern, he doesn't dictate," she said. "You don't get the sense with Santorum that he acknowledges that others feel as strongly as he does (about their positions). I don't see him leaving much space to compromise on some of those issues."

Santorum's views could prove a problem this week as voters in Michigan and Arizona scrutinize the GOP candidates before voting in Tuesday's primaries. Michigan is the most closely watched battleground, since it's a state where Santorum's blue-collar appeal has him in a virtual tie with Mitt Romney, despite it being Romney's boyhood home where his father was governor in the 1960s.

Santorum and Romney are in a statistical dead heat in Michigan, according to an average of five recent polls compiled by realclearpolitics.com.

Some voters and GOP officials have expressed unease about Santorum's comments on birth control. He opposed a provision in the 2010 health care law that required religious-based institutions, such as Catholic hospitals and universities, to provide contraceptives as part of their health coverage despite their doctrine against it.

After Republicans accused the Obama administration of attacking religious freedom, the White House amended the provision to make the insurer — not the religious institution — provide the birth control. Santorum joined other Republicans in objecting to the original provision on religious grounds, but he went on to voice his personal opposition to manufactured contraceptives. In 2006, he described contraceptives as "harmful to women" and "harmful to our society."

Other reservations about him arose when a speech Santorum delivered in 2008 to a Catholic college in Naples, Fla., was recently spotlighted on websites. In it, Santorum said that "Satan is targeting" the United States and influences academia and Christianity. "And of course, we look at the shape of mainline Protestantism in this country and it is a shambles, it is gone from the world of Christianity as I see it," said Santorum, a Roman Catholic.

Santorum's positions trouble some voters.

"A number of the issues Sen. Santorum outlines appear at odds with a number of Americans," said John Green, a University of Akron political science professor who focuses on politics and religion. "When it really matters is among swing voters."

"Politics in America is so off track that any little thing can blow it off," said Dawn Foulke, who runs an assisted living facility in Romeo, Mich. "Why risk it all for someone who can blow it for the Republicans?"

But there's also a significant political counterpoint to such views: Santorum's outspoken stands on hot-button social issues have earned him praise and political support from social conservatives who've longed for an unwavering champion.

"He's always scored 100 percent on our legislative scorecards," said Tom McClusky, senior vice president for Family Research Action, the legislative arm of the Family Research Council, a conservative advocacy group. "He wasn't the guy you had to worry about how he was going to vote. He was the guy helping you get the votes."

Republican presidential candidates championing social issues isn't new. Richard Nixon ran on a law-and-order platform, Ronald Reagan spoke of so-called "welfare queens," and George W. Bush billed himself as a "compassionate conservative." But Santorum has taken social conservatism on the stump to a new level, some analysts say.

"I think the difference here is Sen. Santorum has focused the debate on same-sex marriage, abortion and contraception, issues that Americans are deeply divided on," Green said. "I think Sen. Santorum is fairly militant on the issue of the connection of faith in public policy. Sen. Santorum is a little unusual in that he talks about the conviction of his faith and views so extremely."

Romney strategists haven't mounted a strong challenge to Santorum on social issues, perhaps calculating that could backfire with the GOP conservative base. Instead, they've gone after Santorum's fiscal record during his 16-year House and Senate career.

Romney, supporters say, also needs to also remind voters that he's likely to be the stronger general election candidate.

"Santorum is running a primary campaign. Romney is running a general election campaign," said Stan Grot, clerk of Shelby Township in Michigan. "Santorum is resonating with the base, but when it comes to the election in November, who can beat Obama?"

Santorum is unlikely to relent — and social conservatives say they're tired of hearing their views aren't mainstream. Some are predicting a Santorum surprise.

"I don't agree with the conventional take that if a Republican talks about the sanctity of life, religious freedom, that they are somehow losing issues," said Gary Bauer, a Santorum supporter who heads the socially conservative group American Values. Bauer unsuccessfully sought the Republican presidential nomination in 2000.

A social conservative surge, though, could be difficult to muster. Too many people appear to be thinking like Scott Greenlee, a Grand Rapids, Mich., business consultant.

"I'm a social conservative, but being a fiscal conservative is more important right now," Greenlee said. "Romney is strong on pro-life and right-to-work issues, and he's lived his life in the manner a social conservative would approve of."

At the moment, Greenlee said, economic issues matter most, and "Romney has the background and experience."